require 'repertoire/media/extensions/meta'
require 'repertoire/media/media'
require 'repertoire/compat'

module Repertoire
  module Media
    class Type
      #
      # The name of the Media Type.
      #
      def self.name
        nil
      end

      #
      # The supports URI schemes of the Media Type.
      #
      def self.schemes
        []
      end

      #
      # The directory which is used by the Media Type to store metadata.
      #
      def self.directory
        nil
      end

      protected

      #
      # Register a Media type with a given names.
      #
      # @param [Symbol, String] name
      #   The name to give the media type.
      #
      # @example
      #   known_as :svn
      #
      def self.known_as(name)
        name = name.to_sym

        meta_def(:name) { name }

        Media.types[name] = self
      end

      #
      # Register a Media type for given schemes.
      #
      # @param [Array<String, Symbol>] schemes
      #   The URI schemes supported by the media type.
      #
      # @example
      #   uses_schemes 'svn'
      #
      # @example
      #   uses_schemes 'svn', 'svn+ssh'
      #
      def self.uses_schemes(*schemes)
        meta_def(:schemes) { schemes }

        schemes.each do |scheme|
          scheme = scheme.to_s

          Media.schemes[scheme] = self
        end
      end

      #
      # Registers a Media type that uses a given directory name for storage.
      #
      # @param [String] name
      #   The media storage directory used by the media type.
      #
      # @example
      #   uses_directory '.svn'
      #
      def self.uses_directory(name)
        name = name.to_s

        meta_def(:directory) { name }

        Media.directories[name] = self
      end

      #
      # Changes the current working directory.
      #
      # @param [String] path
      #   The directory to change to.
      #
      # @see http://www.ruby-doc.org/core/classes/Dir.html#M002314
      #
      def self.cd(path)
        Dir.chdir(path.to_s)
      end

      #
      # Changes the current working directory, calls a given block, then
      # changes the current working directory back.
      #
      # @param [String] path
      #   The directory to temporarily switch to.
      #
      # @yield []
      #   If a block is given, it will be called after the current working
      #   directory has been changed.
      #
      def self.switch_dir(path,&block)
        current = Dir.pwd
        
        cd path
        block.call if block
        cd current
      end

      #
      # @see Compat.sh.
      #
      def self.sh(program,*args)
        Compat.sh(program,*args)
      end
    end
  end
end